Moped Army

I'm unfamiliar with how the decompression works on that bike but if it has a separate decompression valve you should be able to just take the cable & lever off, leaving the valve and spring in to close the valve.

if your valve isnt seating properly you can get some valve grinding kit at any autoparts store and clean it up - that should fix it pretty easily.

sometimes the decomp lever just holds open one of the valves - common in 4 strokes, but yours is likely a separate valve. if you bolt it closed just be damn sure that it's not protruding into the engine and going to hit the piston. You'll likely need to rethread the hole to get a good seal. thermal expansion could cause trouble too. It will also create a site for carbon and gunk to build up inside your engine and probably cause hotspots. I don't recommend it.